LM236-2.5

LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode May 1998 LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode General Description The LM136-2.5/LM236-2.5 and LM336-2.5 integrated circuits are precision 2.5V shunt regulator diodes. These monolithic IC voltage references operate as a low-temperature-coefficient 2.5V zener with 0.2Ω dynamic impedance. A third terminal on the LM136-2.5 allows the reference voltage and temperature coefficient to be trimmed easily. The LM136-2.5 series is useful as a precision 2.5V low voltage reference for digital voltmeters, power supplies or op amp circuitry. The 2.5V make it convenient to obtain a stable reference from 5V logic supplies. Further, since the LM136-2.5 operates as a shunt regulator, it can be used as either a positive or negative voltage reference. The LM136-2.5 is rated for operation over −55˚C to +125˚C while the LM236-2.5 is rated over a −25˚C to +85˚C temperature range. The LM336-2.5 is rated for operation over a 0˚C to +70˚C temperature range. See the connection diagrams for available packages. Features n n n n n n n n Low temperature coefficient Wide operating current of 400 µA to 10 mA 0.2Ω dynamic impedance ± 1% initial tolerance available Guaranteed temperature stability Easily trimmed for minimum temperature drift Fast turn-on Three lead transistor package Connection Diagrams TO-92 Plastic Package TO-46 Metal Can Package DS005715-8 Bottom View Order Number LM236Z-2.5, LM236AZ-2.5, LM336Z-2.5 or LM336BZ-2.5 See NS Package Number Z03A DS005715-20 Bottom View Order Number LM136H-2.5, LM136H-2.5/883, LM236H-2.5, LM136AH-2.5, LM136AH-2.5/883 or LM236AH-2.5 See NS Package Number H03H © 1999 National Semiconductor Corporation DS005715 www.national.com Connection Diagrams (Continued) SO Package DS005715-12 Top View Order Number LM236M-2.5, LM236AM-2.5, LM336M-2.5 or LM336BM-2.5 See NS Package Number M08A Typical Applications 2.5V Reference 2.5V Reference with Minimum Temperature Coefficient Wide Input Range Reference DS005715-9 DS005715-11 DS005715-10 Adjust to 2.490V *Any silicon signal diode † www.national.com 2 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Reverse Current Forward Current Storage Temperature 15 mA 10 mA −60˚C to +150˚C Operating Temperature Range (Note 2) LM136 −55˚C to +150˚C LM236 −25˚C to +85˚C LM336 0˚C to +70˚C Soldering Information TO-92 Package (10 sec.) 260˚C TO-46 Package (10 sec.) 300˚C SO Package Vapor Phase (60 sec.) 215˚C Infrared (15 sec.) 220˚C See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” (Appendix D) for other methods of soldering surface mount devices. Electrical Characteristics (Note 3) LM136A-2.5/LM236A-2.5 Parameter Reverse Breakdown Voltage Conditions TA = 25˚C, IR = 1 mA LM136, LM236, LM336 Reverse Breakdown Change With Current Reverse Dynamic Impedance Temperature Stability (Note 4) LM136A, LM236A, LM336B TA = 25˚C, 400 µA≤IR≤10 mA TA = 25˚C, IR = 1 mA, f = 100 Hz VR Adjusted to 2.490V IR = 1 mA, Figure 2 0˚C≤TA≤70˚C (LM336) −25˚C≤TA≤+85˚C (LM236H, LM236Z) −25˚C ≤ TA ≤ +85˚C (LM236M) −55˚C≤TA≤+125˚C (LM136) Reverse Breakdown Change With Current Reverse Dynamic Impedance Long Term Stability IR = 1 mA TA = 25˚C ± 0.1˚C, IR = 1 mA, t = 1000 hrs 0.4 20 1 0.4 20 1.4 Ω ppm 400 µA≤IR≤10 mA 7.5 12 3 18 18 10 3 12 mV mV mV 3.5 9 1.8 6 mV mV 2.440 2.465 2.490 2.490 2.6 0.2 2.540 2.515 6 0.6 2.390 2.440 2.490 2.490 2.6 0.2 2.590 2.540 10 1 V V mV Ω LM136-2.5/LM236-2.5 Min Typ Max Min LM336B-2.5 LM336-2.5 Typ Max Units Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device beyond its specified operating conditions. Note 2: For elevated temperature operation, Tj max is: LM136 LM236 LM336 150˚C 125˚C 100˚C Thermal Resistance θja (Junction to Ambient) θja (Junction to Case) TO-92 180˚C/W (0.4" leads) 170˚C/W (0.125" lead) n/a TO-46 440˚C/W 80˚C/W SO-8 165˚C/W n/a Note 3: Unless otherwise specified, the LM136-2.5 is specified from −55˚C ≤ TA ≤ +125˚C, the LM236-2.5 from −25˚C ≤ TA ≤ +85˚C and the LM336-2.5 from 0˚C ≤ TA ≤ +70˚C. Note 4: Temperature stability for the LM336 and LM236 family is guaranteed by design. Design limits are guaranteed (but not 100% production tested) over the indicated temperature and supply voltage ranges. These limits are not used to calculate outgoing quality levels. Stability is defined as the maximum change in Vref from 25˚C to TA (min) or TA (max). 3 www.national.com Typical Performance Characteristics Reverse Voltage Change Zener Noise Voltage Dynamic Impedance DS005715-21 DS005715-22 DS005715-23 Response Time Reverse Characteristics Forward Characteristics DS005715-24 DS005715-25 DS005715-26 Temperature Drift DS005715-27 www.national.com 4 Application Hints The LM136 series voltage references are much easier to use than ordinary zener diodes. Their low impedance and wide operating current range simplify biasing in almost any circuit. Further, either the breakdown voltage or the temperature coefficient can be adjusted to optimize circuit performance. Figure 1 shows an LM136 with a 10k potentiometer for adjusting the reverse breakdown voltage. With the addition of R1 the breakdown voltage can be adjusted without affecting the temperature coefficient of the device. The adjustment range is usually sufficient to adjust for both the initial device tolerance and inaccuracies in buffer circuitry. If minimum temperature coefficient is desired, two diodes can be added in series with the adjustment potentiometer as shown in Figure 2. When the device is adjusted to 2.490V the temperature coefficient is minimized. Almost any silicon signal diode can be used for this purpose such as a 1N914, 1N4148 or a 1N457. For proper temperature compensation the diodes should be in the same thermal environment as the LM136. It is usually sufficient to mount the diodes near the LM136 on the printed circuit board. The absolute resistance of R1 is not critical and any value from 2k to 20k will work. DS005715-28 FIGURE 1. LM136 With Pot for Adjustment of Breakdown Voltage (Trim Range = ± 120 mV typical) DS005715-29 FIGURE 2. Temperature Coefficient Adjustment (Trim Range = ± 70 mV typical) Low Cost 2 Amp Switching Regulator† DS005715-5 *L1 † 60 turns #16 wire on Arnold Core A-254168-2 Efficiency ≈ 80% 5 www.national.com Application Hints (Continued) Precision Power Regulator with Low Temperature Coefficient DS005715-13 5V Crowbar Trimmed 2.5V Reference with Temperature Coefficient Independent of Breakdown Voltage DS005715-15 *Does DS005715-14 not affect temperature coefficient Adjustable Shunt Regulator DS005715-6 www.national.com 6 Application Hints (Continued) Linear Ohmmeter DS005715-16 7 www.national.com Application Hints (Continued) 2.5V Square Wave Calibrator Op Amp with Output Clamped DS005715-19 5V Buffered Reference DS005715-17 Bipolar Output Reference DS005715-30 Low Noise Buffered Reference DS005715-31 DS005715-18 www.national.com 8 Schematic Diagram DS005715-1 9 www.national.com 10 Physical Dimensions inches (millimeters) unless otherwise noted Order Number LM136H-2.5, LM136H-2.5/883, LM236H-2.5, LM136AH-2.5, LM136AH-2.5/883 or LM236AH-2.5 NS Package Number H03H Small Outline (SO) Package (M) Order Number LM236M-2.5, LM236AM-2.5, LM336M-2.5 or LM336BM-2.5 NS Package Number M08A 11 www.national.com LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode Physical Dimensions inches (millimeters) unless otherwise noted (Continued) TO-92 Plastic Package (Z) Order Number LM236Z-2.5, LM236AZ-2.5, LM336Z-2.5 or LM336BZ-2.5 NS Package Number Z03A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. 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